findings of the reviews of audit stage 2b

Technical review (Opus) and security review (Fable) of 5be109b..5154bba;
reports in the session's scratchpad. Nothing above low from security; one
bug and three risks from the technical review. Migration 0009 is not
deployed, so it was extended.

- Bug: two refusals of one second swapped their NOQUEUE lines (each line
  went to the newest lineless row). AttachRefusalLine now matches the
  client address too (send_log.client_ip, written by the journal milter -
  Postfix's line names the client and the sender, never the login: the
  sasl_username part of the pattern never matched and could be fed by HELO,
  security F1/F2), takes the nearest row in time and the oldest of equals,
  and a line already on a row goes on no other (security F6).
- Waiting lines and recoveries lived only in memory while the saved offset
  moved past them: a stop within 30 s lost them. The tracker now never saves
  an offset past the oldest waiting item in its file (tracker.hold,
  refusalLines.oldest) - for a recovery, the client= line that names its
  login - so they are read again; the "once" guards make that harmless.
- A recovered row whose login the tailer did not see was nobody's: its
  domain_id falls back to the envelope domain's.
- The fingerprint's file identity is the inode alone: the device number can
  change across a host reboot and make the same log look rotated.
- A refused row carries its queue id; UpdateStatus's "newest row" now skips
  refused rows, so a later message with that id does not flip it to sent.
- The alive mark: its age is read first and kept from then on, so asking
  supervisord for 30 s cannot make it stale; the entrypoint removes it with
  the sockets - a container restart is not the check's downtime, and a mark
  from before would have counted the whole outage as "≈".
- Security F3: the sender check prints no ";" of the client's in the From:
  text of its reply, and the tailer reads the envelope after the first ";"
  - Postfix's own text.
- A refused row with a queue id and no stored lines says so (it was told the
  mail.log text of 2.2.0); the fact's em dash is the house hyphen.
- Docs: architecture (client address, no login), guide § Health (warns on
  either count), help topics log and sender-check (design 1ca87f2).
- e2e: refusals_show_postfixs_line wants the refusal's own sender in the
  line; refusal_recovered_from_the_log waits past the tailer's 30 s and
  checks that a refusal the panel wrote got no recovered twin.

Not changed, written down: review 9 (mail.log.1 read to its end at that
moment; postlogd may still write to it until the reload), 10 (a log under
512 bytes has no fingerprint, so places fall back to time briefly after a
rotation), 6 (a 451 at MAIL FROM of another milter reads the same - the
client and sender must match too now), security F5/F12 (info). Review 12:
the refused and closed-by-the-panel variants of out-message were shown to
the owner as pictures of the real templates, not drawn in out-message.html:
the guard ties every drawn screen to a page of the engine, and a variant
has the page's outline.

Evidence on the test server for this tree: go vet clean, go test ./... 23
packages ok, make e2e exit 0 (refusal_recovered_from_the_log 70 s).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/store/migrations/0009_refusal_line.sql

@@ -7,6 +7,12 @@
 -- headers are judged), and its lines are found by it like any other's.
 -- DDL only; a row written earlier has '' and says so on its page.
 ALTER TABLE send_log ADD COLUMN refusal_line TEXT NOT NULL DEFAULT '';
+-- The client a refusal at MAIL FROM came from, as the milter saw it: Postfix's
+-- line names the client and the envelope sender and nothing else - no login
+-- - so the two together are what finds the line's row; the sender alone would
+-- let one application's line land on another's row of the same sender
+-- (security review of stage 2b).
+ALTER TABLE send_log ADD COLUMN client_ip TEXT NOT NULL DEFAULT '';
 
 -- A refusal row the panel did not get to write - the sender check answers 550
 -- and writes the row a moment later, and a panel stopped in between wrote